^ Chapter 2 - Gametogenesis: Conversion of Germ Cells into Male and Female Gameters

Question 0

Female gamete

Answer 0

Oocyte

Question 1

Male gamete

Answer 1

Sperm

Question 2

Zygote=

Answer 2

Sperm + Oocyte

Question 3

Where are the gameters derived from?

Answer 3

Primordial germ cells (PGCs) that are formed in the epiblast during the 2nd week and that move to the wall of the yolk sac

Question 4

When does the gameters move to the yolk sac toward the developing gonads?

Answer 4

During the 4th week

Question 5

When does the gametes arrive the developing gonads?

Answer 5

By the 5th week

Question 6

Synapsis

Answer 6

The process of homologous chromosomes aligning themselves with each other

Question 7

Can the chromosomes be recognized with light microscope before the cell enters mitosis?

Answer 7

Nope

Question 8

Male germ cells

Answer 8

Spermatocyte

Question 9

Female germ cells

Answer 9

Primary oocyte

Question 10

When does the cross overs happen?

Answer 10

Meiosis I

Question 11

What happens in the cross overs?

Answer 11

Interchange of chromatid segments between paired homologous chromosomes

Question 12

Chiasma

Answer 12

X-like structure

Question 13

How many crossovers?

Answer 13

30-40 (1 or 2 per chromosome)

Question 14

How many daughter cells does the primary oocyte give rise to?

Answer 14

4 daughter cells, each with 22 plus 1X chromosome

Question 15

How many of the oocyte daughter cells develops into a mature gamete?

Answer 15

1/4 develops into a mature gamete (secondary oocyte)

Question 16

How many of the oocyte daughter cells are called polar bodies?

Answer 16

3 of the 4 oocyte daughter cells are called polar bodies(first polar bodies?).
They recieve a little cytoplasm and degenerate during subsequent development

Question 17

How many daughter cells does one spermatocyte give rise to?

Answer 17

4 daughter cells:

• two with 22 plus 1X chromosome
• two with 22 plus 1Y chromosome

Question 18

How many of the spermatocyte daughter cells develops into mature gameters?

Answer 18

All 4 develop into mature gameter

Question 19

Oogenesis

Answer 19

The process whereby oogonia differentiate into mature oocytes

Question 20

What happens with the PGCs when they arrive the gonad?

Answer 20

They differentiate into mature oogonia

Question 21

Follicular cells

Answer 21

single, flat, epithelial cells that originate from the surface epithelium covering the ovary

Question 22

Primordial follicle =

Answer 22

Primary oocyte + flat epithelial cells

Question 23

Diplotene stage

Answer 23

A resting stage during prophase that is characterized by a lacy network of chromatin

Question 24

Oocyte maturation inhibitor (OMI)

Answer 24

- Small peptide secreted by follicular cells - Produce the diplotene stage - Prevents the primary oocyte to finish their meiotic division before puberty

Question 25

Follicular cells secret

Answer 25

Oocyte maturation inhibitor (OMI)

Question 26

Which stage is the longest?

Answer 26

The Vesicular (antral) stage

Question 27

What forms the theca folliculi?

Answer 27

The stromal cells

Question 28

Wah secrets the glycoproteins on the surface of oocyte, forming the zona pellucida?

Answer 28

Granulos cells and the oocyte secret glycoproteins

Question 29

Theca interna

Answer 29

Inner secretory cells

Question 30

Theca externa

Answer 30

Outer fibrous capsule

Question 31

What induces the preovulatory growth face?

Answer 31

- Lutenizing hormone (LH)

Question 32

When does the spermatogenesis begin?

Answer 32

It begins at puberty

Question 33

Spermatogenesis

Answer 33

Includes all the events by which spermatogonian are transformed into spermatoza

Question 34

Type B spermatogonia divide to form...

Answer 34

Primary spermatocytes

Question 35

What marks the initiation of spermatogenesis?

Answer 35

Type A spermatogonia

Question 36

What happens when the follicle stimulating hormone (FSH) binds to the Sertoli cells?

Answer 36

They stimulate testicular production and synthesis of intracellular androgen receptor proteins

Question 37

Spermiogenesis, including:

Answer 37

- Formation of the acrosome - Condensation of the nucleus - Formation of neck, middle piece, and tail - Shedding of most of the cytoplasm

Question 38

How many days does the spermatogonium require in order to become a mature spermatozoon?

Answer 38

74 days

Question 39

Type B spermatogonia

Answer 39

- Derive from primordial germ cells | - Gives rise to primary spermatocytes

Question 40

What gives rise to secondary spermatocytes?

Answer 40

Primary spermatocytes

Question 41

Secondary spermatocytes undergo meiosis II and forms?

Answer 41

Spermatids

Question 42

When does the oogenesis begin?

Answer 42

Before birth

Question 43

Trisomies

Answer 43

An extra chromosome

Question 44

Monosomies

Answer 44

Loss of chromosomes

Question 45

Nondisjunction

Answer 45

Homologous chromosomes spearation fails, resulting in one cell recieving too many chromosomes and 1 recieves too few

Question 46

Primordial germ cells differentiate into:

Answer 46

When they arrive the gonads they differentiate into gonads

Question 47

Where does the first polar body lie?

Answer 47

The first polar body lies between the zona pellucida and the cell membrane of the secondary oocyte in the perivitelline space?